CN101900795A - MR imaging apparatus - Google Patents

MR imaging apparatus Download PDF

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Publication number
CN101900795A
CN101900795A CN2010101889490A CN201010188949A CN101900795A CN 101900795 A CN101900795 A CN 101900795A CN 2010101889490 A CN2010101889490 A CN 2010101889490A CN 201010188949 A CN201010188949 A CN 201010188949A CN 101900795 A CN101900795 A CN 101900795A
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CN
China
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mentioned
cooling tube
refrigerant
cooling
magnetic field
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CN2010101889490A
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CN101900795B (en
Inventor
山下正干
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Canon Medical Systems Corp
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Toshiba Corp
Toshiba Medical Systems Corp
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00Arrangements or instruments for measuring magnetic variables
    • G01R33/20Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/385Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils
    • G01R33/3856Means for cooling the gradient coils or thermal shielding of the gradient coils
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00Arrangements or instruments for measuring magnetic variables
    • G01R33/20Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/387Compensation of inhomogeneities
    • G01R33/3873Compensation of inhomogeneities using ferromagnetic bodies ; Passive shimming
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00Arrangements or instruments for measuring magnetic variables
    • G01R33/20Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42Screening
    • G01R33/421Screening of main or gradient magnetic field
    • G01R33/4215Screening of main or gradient magnetic field of the gradient magnetic field, e.g. using passive or active shielding of the gradient magnetic field

Abstract

The invention provides a kind of MR imaging apparatus, this MR imaging apparatus has the gradient magnetic field coil that the subject of placing in the static magnetic field is applied leaning magnetic field.And the 1st cooling tube is set in the gradient magnetic field coil, makes the refrigerant circulation on prescribed direction.In addition, the 2nd cooling system to be being configured in the gradient magnetic field coil with the 1st cooling tube mode arranged side by side, makes refrigerant round-robin side make the refrigerant circulation in the opposite direction with the 1st cooling tube.

Description

MR imaging apparatus
The application is based on Japanese patent application No.2009-130953 that submitted on May 29th, 2009 and the Japanese patent application No.2010-094217 that submitted on April 15th, 2010 and to require it be right of priority, and its full content is by reference in conjunction with in this application.
Technical field
The present invention relates to MR imaging apparatus.
Background technology
MR imaging apparatus is to utilize the device of magnetic resonance phenomenon image conversion in subject.This MR imaging apparatus possess camera watch region produce the static field magnet of static magnetic field or to static magnetic field in the subject placed apply the gradient magnetic field coil of leaning magnetic field, the various unit such as radio-frequency coil of receiving magnetic resonance signals from the subject that has applied leaning magnetic field.
In these various unit, gradient magnetic field coil is heating tempestuously owing to repeat to supply with pulse current in shooting.Particularly, in recent years, along with the high speed of imaging technique, the high speed of the switch of leaning magnetic field and the high strength of leaning magnetic field become necessary, and the heating of gradient magnetic field coil is more remarkable.
The heating of gradient magnetic field coil might exert an influence to the image quality of image of shooting, and the subject that becomes the shooting object is brought misery.Therefore, in the past, proposed to be used to be suppressed at the various technology of the heating of shooting medium dip field coil.For example, have by making refrigerant circulation in the cooling tube that in gradient magnetic field coil, is provided with, thereby in shooting, make the technology (for example, with reference to TOHKEMY 2006-311957 communique) of gradient magnetic field coil cooling.
Yet as follows in MR imaging apparatus in the past, existence can't the impartial problem of cooling off gradient magnetic field coil.
Particularly, in above-mentioned technology in the past, generally in gradient magnetic field coil, the inlet of cooling tube disposes at opposition side respectively with outlet.And, the refrigerant that flows in the cooling tube from side's side inflow of gradient magnetic field coil during flow out from opposition side, thereby the heat temperature that the absorption dip field coil produces rises gradually.Therefore, near the inlet of cooling tube with outlet near, the temperature of refrigerant produces difference.Its result produces thermograde in the chilled water that flows in gradient magnetic field coil, can't cool off gradient magnetic field coil equably.
The present invention is in view of above-mentioned and finish, and its purpose is: provide can impartial cooling gradient magnetic field coil MR imaging apparatus.
Summary of the invention
Provide a kind of MR imaging apparatus according to an embodiment of the invention, it is characterized in that, comprising: gradient magnetic field coil applies leaning magnetic field to the subject of placing in the static magnetic field; The 1st cooling tube is set in the above-mentioned gradient magnetic field coil, makes the refrigerant circulation on prescribed direction; The 2nd cooling tube being set in the above-mentioned gradient magnetic field coil with above-mentioned the 1st cooling tube mode arranged side by side, makes refrigerant round-robin side make the refrigerant circulation in the opposite direction with above-mentioned the 1st cooling tube.
To propose other purpose of the present invention and advantage in the following description, partial content can become from the description of instructions obviously, perhaps can clear and definite foregoing by implementing the present invention.Can realize and obtain objects and advantages of the present invention by means and the combination of hereinafter pointing out in detail.
Description of drawings
The accompanying drawing that is combined in here and constitutes the part of instructions is described presently preferred embodiments of the invention, and with above-mentioned summary description and following detailed description of the preferred embodiment together is used for illustrating principle of the present invention.
Fig. 1 is the figure that is used to illustrate the summary of the MRI device relevant with present embodiment.
Fig. 2 is the structural drawing of the structure of the expression MRI device relevant with present embodiment.
Fig. 3 is the stereographic map of the structure of the expression gradient magnetic field coil relevant with present embodiment.
Fig. 4 is the structural drawing of the inner structure of the expression gradient magnetic field coil relevant with present embodiment.
Fig. 5 is the figure of the circulating path of the chilled water in the expression MRI device relevant with present embodiment.
Fig. 6 is the figure of other examples of the circulating path of the chilled water in the expression MRI device relevant with present embodiment.
Fig. 7 is the figure of an example of the configuration of the cooling tube in the expression main coil side cooling system relevant with present embodiment.
Fig. 8 is the figure of an example of expression entrance side menifold relevant with present embodiment and outlet side menifold.
Fig. 9 is the figure of other examples of the configuration of expression 1st cooling tube relevant with present embodiment and the 2nd cooling tube.
Figure 10 is the figure of other examples of expression entrance side menifold relevant with present embodiment and outlet side menifold.
Figure 11 is the figure of the embodiment of the situation of 33 ground use the 1st cooling tubes of expression difference and the 2nd cooling tube.
Embodiment
Below, describe the embodiment of MR imaging apparatus related to the present invention (below, be called " MRI (Magnetic Resonance Imaging) device ") with reference to the accompanying drawings in detail.In addition, be not to limit of the present invention by embodiment shown below.In addition, in embodiment shown below, describe at the situation that makes water (below, be called " chilled water ") as the refrigerant that is used to cool off gradient magnetic field coil.
At first, the summary at the MRI device relevant with present embodiment describes.Fig. 1 is the figure that is used to illustrate the summary of the MRI device relevant with present embodiment.The MRI device relevant with present embodiment has the gradient magnetic field coil that the subject of placing in the static magnetic field is applied leaning magnetic field.In the present embodiment, gradient magnetic field coil is ASGC (Actively Shielded Gradient Coil: active shield type gradient magnetic field coil).
At this, in gradient magnetic field coil, the 1st cooling system and the 2nd cooling system of a plurality of cooling tubes that have configuration arranged side by side respectively is set.And in the present embodiment, as shown in Figure 1, the 1st cooling system and the 2nd cooling system in the opposite direction make the chilled water circulation respectively.
Thus, in gradient magnetic field coil, in the zone that the temperature of mobile chilled water is low in the 1st cooling system, the temperature of the chilled water that flows in the 2nd cooling system raises, on the contrary, in the zone that the temperature of mobile chilled water is high in the 1st cooling system, the temperature of the chilled water that flows in the 2nd cooling system descends.Therefore, produce the heat interchange between the cooling tube, but, the situation of the temperature rising of side's side can not take place as gradient magnetic field coil integral body.Its result, owing to can prevent from chilled water, to produce thermograde, therefore can impartial cooling gradient magnetic field coil.
Secondly, the structure at the MRI device 100 relevant with present embodiment describes.Fig. 2 is the structural drawing of the structure of the expression MRI device 100 relevant with present embodiment.Shown in figure, this MRI device 100 has static field magnet 10, gradient magnetic field coil 20, RF coil 30, bed board 40, leaning magnetic field power supply 50, sending part 60, acceptance division 65, sequence control device 70, computer system 80, cooling device 90.
Static field magnet 10 has the vacuum tank 11 of general cylindrical shape shape and the superconducting coil 12 of the liquid dipping that is cooled in vacuum tank 11, produce static magnetic field in as the hole (space of the cylinder interior of static field magnet 10) of camera watch region.
Gradient magnetic field coil 20 forms the general cylindrical shape shape, is fixed on the inboard of static field magnet 10.This gradient magnetic field coil 20 has the electric current of supplying with by leaning magnetic field power supply 50 and apply the main coil 21 of leaning magnetic field and the potted coil 22 of the leakage field of eliminating main coil 21 on X-axis, Y-axis, Z-direction.
At this, between main coil 21 and potted coil 22, form the pad pallet and insert guiding piece 23.Insert in the guiding piece 23 at this pad pallet, insert and held the pad pallet 24 that is used for the uneven iron gasket 25 in magnetic field in the correction hole.At the structure of this gradient magnetic field coil 20, the back is elaborated.
RF coil 30 is in the inboard of gradient magnetic field coil 20, to be fixed across the relative mode of subject P.The RF pulse that the 30 couples of subject P of this RF coil irradiation sending part 60 is supplied with, and, the magnetic resonance signal of emitting in the subject P received by the excitation of hydrogen nuclei.
Bed board 40 is configured to move to horizontal direction on not shown bed in advance, thereby mounting subject P moves in the hole when photography.Leaning magnetic field power supply 50 is according to the indication from sequence control device 70, to gradient magnetic field coil 20 supplying electric currents.
Sending part 60 is supplied with the RF pulse according to the indication from sequence control device 70 to RF coil 30.Acceptance division 65 detects by the received magnetic resonance signal of RF coil 30, sequence control device 70 is sent make the obtained raw data of detected magnetic resonance signal digitizing.
Sequence control device 70 carries out the scanning of subject P by driving leaning magnetic field power supply 50, sending part 60 and acceptance division 65 respectively under the control of computer system 80.And the result that sequence control device 70 scans when sending raw data from acceptance division 65, sends to computer system 80 with its raw data.
Computer system 80 control MRI devices 100 integral body.Particularly, this computer system 80 have from the operator accept there various inputs input part or according to the imaging conditions of there importing from the operator make that sequence control device 70 is carried out the sequence control part of scanning, the storage part of image reconstruction portion, the storage of the raw data reconstructed image that sends according to sequence control device 70 image after rebuilding etc., show the display part of the various information such as image after rebuilding, according to the master control part of the action of controlling each function portion from operator's indication etc.
The cooling tube that cooling device 90 is provided with in gradient magnetic field coil 20 is supplied with chilled water.Particularly, cooling device 90 is supplied with chilled water to the 1st cooling system and the 2nd cooling system that gradient magnetic field coil 20 is had respectively.At this, cooling device 90 becomes reverse direction respectively for the direction of the chilled water that flows in the direction that makes in the 1st cooling system chilled water that flows and the 2nd cooling system, and to each cooling system supply chilled water.
Secondly, the structure at gradient magnetic field coil shown in Figure 2 20 describes.Fig. 3 is the stereographic map of the structure of the expression gradient magnetic field coil 20 relevant with present embodiment.Shown in figure, gradient magnetic field coil 20 has the main coil 21 and potted coil 22 that forms the general cylindrical shape shape.And, between these two coils, form a plurality of pad pallets and insert guiding piece 23.
It is the through hole that forms opening in the both ends of the surface of gradient magnetic field coil 20 that the pad pallet inserts guiding piece 23, is formed on the whole length direction of gradient magnetic field coil 20.This pad pallet inserts guiding piece 23 in the zone of main coil 21 and potted coil 22, forms uniformly-spaced in a circumferential direction in mode parallel to each other.And, insert in the guiding piece 23 at this pad pallet, insert pad pallet 24.
Pad pallet 24 uses to be made as the resin of non magnetic and non-conductive material, forms roughly bar-shaped.The iron gasket 25 that in this pad pallet 24, holds the regulation number.And pad pallet 24 is inserted into the pad pallet and inserts in the guiding piece 23, and is fixed on the central portion of gradient magnetic field coil 20 respectively.In addition, in Fig. 3, omitted diagram, but in gradient magnetic field coil 20 along drum, bury cooling tube underground curl.
Fig. 4 is the structural drawing of the inner structure of the expression gradient magnetic field coil 20 relevant with present embodiment.With illustrating the part of gradient magnetic field coil 20, show the outside of drum with the upside among the figure, show the inboard of drum with the downside among the figure.
As shown in Figure 4, in gradient magnetic field coil 20, insert between guiding piece 23 and the main coil 21, main coil side cooling system 26 is set at the pad pallet.In addition, insert between guiding piece 23 and the potted coil 22, potted coil side cooling system 27 is set at the pad pallet.At this, main coil side cooling system 26 and potted coil side cooling system 27 have a plurality of cooling tubes of burying curl underground respectively.
Particularly, main coil side cooling system 26 has the 1st cooling tube and the 2nd cooling tube to be provided with the 1st cooling tube mode arranged side by side.The 1st cooling tube makes the chilled water circulation on the direction (direction of dotted arrow shown in Figure 4) of regulation, the 2nd cooling tube makes chilled water round-robin side make the chilled water circulation on (direction of solid arrow shown in Figure 4) in the opposite direction with the 1st cooling tube.In addition, potted coil side cooling system 27 has the 1st cooling tube and the 2nd cooling tube too.
That is, in gradient magnetic field coil 20, configuration main coil side cooling system 26 between main coil 21 and iron gasket 25, configuration shielding coil sides cooling system 27 between potted coil 22 and iron gasket 25.And main coil side cooling system 26 disposes across iron gasket 25 respectively with potted coil side cooling system 27.Thus, the heat that is produced by main coil 21 and potted coil 22 is difficult to be transmitted to iron gasket 25.
Secondly, the circulating path at the chilled water in the MRI device 100 relevant with present embodiment describes.Fig. 5 is the figure of the circulating path of the chilled water in the expression MRI device 100 relevant with present embodiment.As shown in Figure 5, for example, MRI device 100 possesses refrigerant supply pipe 90a, 90b and 90c and valve 90d.Refrigerant supply pipe 90a one end is connected with cooling device 90, and the other end is connected with valve 90d.Refrigerant supply pipe 90b one end is connected with valve 90d, and the other end is connected with the side of gradient magnetic field coil 20.Refrigerant supply pipe 90c one end is connected with valve 90d, and the other end is connected with the side of gradient magnetic field coil 20.At this, refrigerant supply pipe 90c is connected with respect to the opposition side of gradient magnetic field coil 20 with refrigerant supply pipe 90b.
In addition, MRI device 100 possesses refrigerant vent pipe 90e, 90f and 90g and valve 90h.Refrigerant vent pipe 90e one end is connected with the side of gradient magnetic field coil 20, and the other end is connected with valve 90h.Refrigerant vent pipe 90f one end is connected with the side of gradient magnetic field coil 20, and the other end is connected with valve 90h.At this, refrigerant vent pipe 90f is connected with the opposition side of refrigerant vent pipe 90e with respect to gradient magnetic field coil 20.Refrigerant vent pipe 90g one end is connected with valve 90h, and the other end is connected with cooling device 90.
And refrigerant supply pipe 90a will flow into valve 90d from the chilled water that cooling device 90 is supplied with.Valve 90d will become 2 streams from the chilled water difference that refrigerant supply pipe 90a flows into, and the chilled water of a stream is flowed into refrigerant supply pipe 90b, and the chilled water of another stream is flowed into refrigerant supply pipe 90c.Refrigerant supply pipe 90b will supply to main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately from the chilled water that valve 90d flows into.Cooling tube 90c makes the chilled water that flows into from valve 90d flow into main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately.
In addition, the refrigerant vent pipe 90e chilled water that will flow out from main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately flows into valve 90h.The chilled water that refrigerant vent pipe 90f will flow out from main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately flows into valve 90h.Valve 90h makes from the chilled water interflow of refrigerant vent pipe 90e and 90f inflow and flow into refrigerant vent pipe 90g.Refrigerant supply pipe 90g will turn back to cooling device 90 from the chilled water that valve 90h flows into.
Thus, recirculated cooling water in main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately.In addition, also recirculated cooling water in main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately.
Like this, in the present embodiment, the stream difference of the chilled water that refrigerant supply pipe 90a, 90b and 90c will supply with from cooling device 90 becomes 2 streams, the chilled water that flows in the stream is supplied to the 1st cooling tube from a side of gradient magnetic field coil 20, and chilled water another side from gradient magnetic field coil 20 supplies to the 2nd cooling tube with flowing in the 2nd stream.That is, in the present embodiment, in gradient magnetic field coil 20, chilled water is supplied to the 1st cooling system and the 2nd cooling system from opposition side respectively.
In addition, the circulating path of chilled water is not limited in this.Fig. 6 is the figure of other examples of the circulating path of the chilled water in the expression MRI device relevant with present embodiment.Example shown in Figure 6 shows the situation that MRI device 100 possesses 2 cooling devices 91 and 92.At this moment, for example, MRI device 100 possesses refrigerant supply pipe 91a and 92a and refrigerant vent pipe 91b and 92b.
Refrigerant supply pipe 91a one end is connected with cooling device 91, and the other end is connected with the side of gradient magnetic field coil 20.Refrigerant supply pipe 92a one end is connected with cooling device 92, and the other end is connected with the side of gradient magnetic field coil 20.At this, refrigerant supply pipe 92a is connected with respect to the opposition side of gradient magnetic field coil 20 with refrigerant supply pipe 91a.
Refrigerant vent pipe 91b one end is connected with the side of leaning magnetic field 20, and the other end is connected with cooling device 91.Refrigerant vent pipe 92b one end is connected with the side of gradient magnetic field coil 20, and the other end is connected with cooling device 92.At this, refrigerant vent pipe 92b is connected with respect to the opposition side of gradient magnetic field coil 20 with refrigerant vent pipe 92b.
And refrigerant supply pipe 91a makes the chilled water of supplying with from cooling device 91 flow into main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately.In addition, the refrigerant vent pipe 91b chilled water that will flow out from main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately turns back to cooling device 91.Thus, recirculated cooling water in main coil side cooling system 26 and potted coil side cooling system 27 the 1st cooling tube separately.
In addition, refrigerant supply pipe 92a makes the chilled water of supplying with from cooling device 92 flow into main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately.In addition, the refrigerant vent pipe 92b chilled water that will flow out from main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately turns back to cooling device 92.Thus, recirculated cooling water in main coil side cooling system 26 and potted coil side cooling system 27 the 2nd cooling tube separately.
Like this, for example, cooling device 91 supplies to the 1st cooling tube with chilled water from a side of gradient magnetic field coil 20.In addition, cooling device 92 supplies to the 2nd cooling tube with chilled water from another side of leaning magnetic field.In this example, in gradient magnetic field coil 20, the 1st cooling system and the 2nd cooling system also are supplied to chilled water from opposition side respectively.
Secondly, the configuration at the cooling tube in main coil side cooling system 26 and the potted coil side cooling system 27 describes.In addition, because the configuration of the cooling tube in configuration and the potted coil side cooling system 27 of the cooling tube in the main coil side cooling system 26 is identical respectively, so, illustrate main coil side cooling system 26 at this.
Fig. 7 is the figure of an example of the configuration of the cooling tube in the main coil side cooling system 26 of the expression gradient magnetic field coil 20 relevant with present embodiment.With illustrating the situation of using 2 by 2 the 1st cooling tube and the 2nd cooling tube respectively.For example, shown in figure, in main coil side cooling system 26, alternate configurations the 1st cooling tube 26a and the 2nd cooling tube 26b.
In addition, in Fig. 7, omit diagram, but with outlet menifold (branch pipe) is set respectively at the inlet of each cooling tube.To become the regulation ramification number from the chilled water difference that cooling device 90 is supplied with at the set menifold in porch (below, be called " entrance side menifold "), it will be flow into respectively in each cooling tube.Make the chilled water interflow of from each cooling tube, flowing out and supply to cooling device 90 at the set menifold of outlet (below, be called " outlet side menifold ").
Fig. 8 is the figure of an example of expression entrance side menifold relevant with present embodiment and outlet side menifold.With illustrating the menifold that is provided with in the cooling tube of main coil side cooling system 26 shown in Figure 7.For example, as shown in Figure 8, in main coil side cooling system 26, set into oral-lateral menifold 28a, set out oral-lateral menifold 29b in the outlet of the 2nd cooling tube 26b at the inlet of the 1st cooling tube 26a.
Entrance side menifold 28a will become 2 streams from the chilled water difference that cooling device 90 is supplied with, and it is flow into respectively among each the 1st cooling tube 26a.In addition, though in Fig. 8 diagram not, the entrance side menifold that is provided with at the inlet of the 2nd cooling tube 26b will become 2 streams from the chilled water difference that cooling device 90 is supplied with too, and it is flow into respectively respectively in the 2nd cooling tube.
On the other hand, outlet side menifold 29b makes the chilled water interflow of flowing out and supplies to cooling device 90 from each the 2nd cooling tube 26b.In addition, though in Fig. 8 diagram not, the outlet side menifold that is provided with in the outlet of the 1st cooling tube 26a collaborates the chilled water that flows out and sends to cooling device 90 too from each the 1st cooling tube 26a.
At this, the ramification number of the caliber of each cooling tube, the length of each cooling tube, each menifold respectively so that the identical respectively mode of the pressure loss of each cooling tube decide.For example, make the ramification number of the length of caliber, each cooling tube of each cooling tube and each menifold identical.In addition, for example thick by the caliber that makes the short cooling tube of length in the length of any cooling tube in short-term than the caliber of other cooling tubes than the length of other cooling tubes, thus make the pressure loss of each cooling tube identical.In addition, for example thin by the caliber that makes the cooling tube that is connected with the many branch pipe of ramification number in the ramification number of arbitrary menifold for a long time than the caliber of the cooling tube that is connected with other menifolds than the ramification number of other menifolds, thus make the pressure loss of each cooling tube identical.Like this, identical by the pressure loss that makes each cooling tube, thus the flow that flow into the chilled water in each cooling tube is become necessarily.
As mentioned above, in the present embodiment, the 1st cooling tube is set in the gradient magnetic field coil 20, makes the refrigerant cooling on prescribed direction.In addition, the 2nd cooling system to be being set in the gradient magnetic field coil 20 with the 1st cooling tube mode arranged side by side, makes refrigerant round-robin side make the refrigerant circulation in the opposite direction with the 1st cooling tube 26a.Therefore, according to present embodiment, owing to can prevent from chilled water, to produce thermograde, therefore can impartial cooling gradient magnetic field coil.
In addition, in the present embodiment, the 1st cooling tube and the 2nd cooling tube are configured between main coil 21 and the iron gasket 25 respectively and between potted coil 22 and the iron gasket 25.Therefore, according to present embodiment, can prevent from iron gasket 25, to produce thermograde.The temperature variation of well-known iron gasket 25 is owing to be to cause the magnetic field homogeneity change, therefore can the image quality of the image of shooting be exerted an influence.In the present embodiment, can prevent that the result who produces thermograde in iron gasket 25 from can improve magnetic field homogeneity, therefore can obtain the image of stable image quality.
In addition, according to present embodiment, alternate configurations the 1st cooling tube and the 2nd cooling tube.Therefore, according to present embodiment,, therefore can cool off gradient magnetic field coil more equably owing to can make the Temperature Distribution of chilled water more even.
In addition, according to present embodiment, so that the identical respectively mode of the pressure loss of each cooling tube determines the caliber of each cooling tube, the length of each cooling tube, the ramification number of each menifold respectively.Therefore, according to present embodiment, become necessarily owing to flow into the flow of the chilled water of each cooling tube, therefore more the high precision equalization is cooled off gradient magnetic field coil 20.
In addition, in the above-described embodiments, be illustrated at the situation of alternate configurations the 1st cooling tube and the 2nd cooling tube, but the present invention is not limited to this.For example, also can alternate configurations the group and the group of a plurality of the 2nd cooling tubes side by side of a plurality of the 1st cooling tubes side by side.
Fig. 9 is the figure of other examples of the configuration of expression 1st cooling tube relevant with present embodiment and the 2nd cooling tube.Also illustrate main coil side cooling system 26 at this.For example, as shown in Figure 9, in main coil side cooling system 26, the group that also can alternate configurations 2 article of the 1st cooling tube arranged side by side and the group of 2 article of the 2nd cooling tube arranged side by side.Like this, many cooling tubes as group, are pressed the configuration set cooling tube to it, thereby do not intersected at the part cooling tube of menifold.
Figure 10 is the figure of other examples of expression entrance side menifold 28a relevant with present embodiment and outlet side menifold 29b.With illustrating the menifold that is provided with in the cooling tube of main coil side cooling system 26 shown in Figure 9.For example, as shown in figure 10,, adjoin 2 article of the 2nd cooling tube 26b of configuration, entrance side menifold 28a and outlet side menifold 29b are not configured across by adjoining 2 article of the 1st cooling tube 26a of configuration.Thus, save space ground difference cooling tube more.In addition, can use undersized menifold.
In addition, also each menifold can be separately positioned on the inside of above-mentioned gradient magnetic field coil.Thus, more can be at little space difference cooling tube.
In addition, in the above-described embodiments, so that the identical respectively mode of the pressure loss of each cooling tube determines the caliber of each cooling tube, the length of each cooling tube, the ramification number of each menifold respectively.Yet the present invention is not limited to this.For example, also can determine the caliber of each cooling tube, the length of each cooling tube, the ramification number of each menifold respectively so that the cooling tube that comprises in the pressure loss of the cooling tube that comprises in the main coil side cooling system 26 and the potted coil side cooling system 27 is compared the mode that diminishes.Thus, can make the flow of the chilled water that flow into main coil side cooling system 26 compare change with potted coil side cooling system 27 greatly.Therefore main coil 21 can become big, thereby cool off tilt coil 20 more equably because to compare heating bigger with potted coil 22 by the flow that makes the chilled water that flow into main coil side cooling system 26.In addition, can effectively cool off gradient magnetic field coil 20 with the flow that limits.
In addition, in the above-described embodiments, at using 2 by 2 the situation of the 1st cooling tube and the 2nd cooling tube to be illustrated respectively, but the bar number of each cooling tube is not limited thereto.Figure 11 is the figure of the embodiment of the situation of 33 ground use the 1st cooling tubes of expression difference and the 2nd cooling tube.With illustrating the 1st cooling tube 26a in the main coil side cooling system 26 and the configuration of the 2nd cooling tube 26b.
As shown in figure 11, when 33 ground used the 1st cooling tube 26a and the 2nd cooling tube 26b respectively, entrance side menifold 28a became 3 streams with the chilled water difference, made it flow into each the 1st cooling tube 26a respectively.In addition, outlet side menifold 29a makes the chilled water interflow of flowing out and supplies to cooling device 90 from each the 2nd cooling tube 26a.In addition, entrance side menifold 28b becomes 3 streams with the chilled water difference, makes it flow into each the 2nd cooling tube 26b respectively.In addition, outlet side menifold 29b makes the chilled water interflow of flowing out and supplies to cooling device 90 from each the 2nd cooling tube 26b.
Like this, owing to, make the contraction in length of each cooling tube, therefore can suppress the pressure loss of each cooling tube by increasing the ramification number of chilled water.Its result owing to can increase the flow of chilled water, therefore can more effectively cool off gradient magnetic field coil 20.
In addition, in the above-described embodiments, be illustrated, but the present invention is not limited to this in gradient magnetic field coil 20, cooling tube being configured to spiral helicine situation.For example, also can use equally in the situation of the length direction configuration arranged side by side of gradient magnetic field coil 20 at cooling tube.
Also have, the combination according to disclosed a plurality of inscape that suits in the above-mentioned embodiment can form various inventions.For example: both can eliminate several inscapes of the whole inscapes that from embodiment, show, and can suitably make up the inscape in the different embodiments again.
Those skilled in the art expect other advantage and alter mode easily.Therefore, the present invention is not limited to the detail and the representational embodiment that illustrate and illustrate here with regard to its wideer aspect.Therefore, do not deviate from by appending claims with and the situation of the spirit and scope of the general inventive concept that limits of equivalent under, can carry out various modifications.

Claims (20)

1. a MR imaging apparatus is characterized in that, comprising:
Gradient magnetic field coil applies leaning magnetic field to the subject of placing in the static magnetic field;
The 1st cooling tube is set in the above-mentioned gradient magnetic field coil, makes the refrigerant circulation on prescribed direction;
The 2nd cooling tube being set in the above-mentioned gradient magnetic field coil with above-mentioned the 1st cooling tube mode arranged side by side, makes refrigerant round-robin side make the refrigerant circulation in the opposite direction with above-mentioned the 1st cooling tube.
2. MR imaging apparatus according to claim 1 is characterized in that:
Above-mentioned gradient magnetic field coil has coil that produces regulation magnetic field and the iron gasket of adjusting above-mentioned static magnetic field uniformity coefficient,
Above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube are configured in respectively between above-mentioned coil and the above-mentioned iron gasket.
3. MR imaging apparatus according to claim 1 is characterized in that:
Above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube are set up a plurality of respectively,
The 1st cooling tube and the 2nd cooling tube alternate configurations.
4. MR imaging apparatus according to claim 2 is characterized in that:
Above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube are set up a plurality of respectively,
The 1st cooling tube and the 2nd cooling tube alternate configurations.
5. MR imaging apparatus according to claim 1 is characterized in that:
Above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube are set up a plurality of respectively,
The group of a plurality of the 1st cooling tubes and the group alternate configurations of a plurality of the 2nd cooling tubes side by side side by side.
6. MR imaging apparatus according to claim 2 is characterized in that:
Above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube are set up a plurality of respectively,
The group of a plurality of the 1st cooling tubes and the group alternate configurations of a plurality of the 2nd cooling tubes side by side side by side.
7. MR imaging apparatus according to claim 3 is characterized in that, comprising:
The 1st refrigerant branch pipe becomes the regulation ramification number with the refrigerant difference and makes it flow into a plurality of the 1st cooling tubes;
The 2nd refrigerant branch pipe becomes the regulation ramification number with the refrigerant difference and makes it flow into a plurality of the 2nd cooling tubes,
So that the identical respectively mode of the pressure loss of above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube determines the caliber of each cooling tube, the length of each cooling tube, the ramification number of each refrigerant branch pipe respectively.
8. MR imaging apparatus according to claim 5 is characterized in that, also comprises:
The 1st refrigerant branch pipe becomes the regulation ramification number with the refrigerant difference and makes it flow into a plurality of the 1st cooling tubes;
The 2nd refrigerant branch pipe becomes the regulation ramification number with the refrigerant difference and makes it flow into a plurality of the 2nd cooling tubes,
So that the identical respectively mode of the pressure loss of above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube determines the caliber of each cooling tube, the length of each cooling tube, the ramification number of each refrigerant branch pipe respectively.
9. MR imaging apparatus according to claim 7 is characterized in that:
Above-mentioned gradient magnetic field coil has main coil and potted coil, possesses:
Main coil side cooling system comprises above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube that dispose side by side along above-mentioned main coil;
Potted coil side cooling system comprises above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube that dispose side by side along above-mentioned potted coil,
So that the cooling tube that comprises in the pressure loss of the cooling tube that comprises in the above-mentioned main coil side cooling system and the above-mentioned potted coil side cooling system is compared the mode that diminishes, determine the caliber of each cooling tube, the length of each cooling tube, the ramification number of each refrigerant branch pipe respectively.
10. MR imaging apparatus according to claim 8 is characterized in that:
Above-mentioned gradient magnetic field coil has main coil and potted coil, possesses:
Main coil side cooling system comprises above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube that dispose side by side along above-mentioned main coil;
Potted coil side cooling system comprises above-mentioned the 1st cooling tube and above-mentioned the 2nd cooling tube that dispose side by side along above-mentioned potted coil,
So that the cooling tube that comprises in the pressure loss of the cooling tube that comprises in the above-mentioned main coil side cooling system and the above-mentioned potted coil side cooling system is compared the mode that diminishes, determine the caliber of each cooling tube, the length of each cooling tube, the ramification number of each refrigerant branch pipe respectively.
11. MR imaging apparatus according to claim 7 is characterized in that:
Above-mentioned the 1st refrigerant branch pipe and above-mentioned the 2nd refrigerant branch pipe are set at the inside of above-mentioned gradient magnetic field coil respectively.
12. MR imaging apparatus according to claim 9 is characterized in that:
Above-mentioned the 1st refrigerant branch pipe and above-mentioned the 2nd refrigerant branch pipe are set at the inside of above-mentioned gradient magnetic field coil respectively.
13. MR imaging apparatus according to claim 1 is characterized in that, comprising:
Cooling device is supplied with refrigerant;
The refrigerant supply pipe, the stream difference of the refrigerant that will supply with from above-mentioned cooling device becomes the 1st stream and the 2nd stream, the side of refrigerant mobile in above-mentioned the 1st stream from above-mentioned gradient magnetic field coil supplied to above-mentioned the 1st cooling tube, refrigerant mobile in above-mentioned the 2nd stream another side from above-mentioned gradient magnetic field coil is supplied to above-mentioned the 2nd cooling tube.
14. MR imaging apparatus according to claim 2 is characterized in that, comprising:
Cooling device is supplied with refrigerant;
The refrigerant supply pipe, the stream difference of the refrigerant that will supply with from above-mentioned cooling device becomes the 1st stream and the 2nd stream, the side of refrigerant mobile in above-mentioned the 1st stream from above-mentioned gradient magnetic field coil supplied to above-mentioned the 1st cooling tube, refrigerant mobile in above-mentioned the 2nd stream another side from above-mentioned gradient magnetic field coil is supplied to above-mentioned the 2nd cooling tube.
15. MR imaging apparatus according to claim 3 is characterized in that, comprising:
Cooling device is supplied with refrigerant;
The refrigerant supply pipe, the stream difference of the refrigerant that will supply with from above-mentioned cooling device becomes the 1st stream and the 2nd stream, the side of refrigerant mobile in above-mentioned the 1st stream from above-mentioned gradient magnetic field coil supplied to above-mentioned the 1st cooling tube, refrigerant mobile in above-mentioned the 2nd stream another side from above-mentioned gradient magnetic field coil is supplied to above-mentioned the 2nd cooling tube.
16. MR imaging apparatus according to claim 5 is characterized in that, comprising:
Cooling device is supplied with refrigerant;
The refrigerant supply pipe, the stream difference of the refrigerant that will supply with from above-mentioned cooling device becomes the 1st stream and the 2nd stream, the side of refrigerant mobile in above-mentioned the 1st stream from above-mentioned gradient magnetic field coil supplied to above-mentioned the 1st cooling tube, refrigerant mobile in above-mentioned the 2nd stream another side from above-mentioned gradient magnetic field coil is supplied to above-mentioned the 2nd cooling tube.
17. MR imaging apparatus according to claim 1 is characterized in that, comprising:
The 1st cooling device supplies to above-mentioned the 1st cooling tube with refrigerant from a side of above-mentioned gradient magnetic field coil;
The 2nd cooling device supplies to above-mentioned the 2nd cooling tube with refrigerant from another side of above-mentioned gradient magnetic field coil.
18. MR imaging apparatus according to claim 2 is characterized in that, comprising:
The 1st cooling device supplies to above-mentioned the 1st cooling tube with refrigerant from a side of above-mentioned gradient magnetic field coil;
The 2nd cooling device supplies to above-mentioned the 2nd cooling tube with refrigerant from another side of above-mentioned gradient magnetic field coil.
19. MR imaging apparatus according to claim 3 is characterized in that, comprising:
The 1st cooling device supplies to above-mentioned the 1st cooling tube with refrigerant from a side of above-mentioned gradient magnetic field coil;
The 2nd cooling device supplies to above-mentioned the 2nd cooling tube with refrigerant from another side of above-mentioned gradient magnetic field coil.
20. MR imaging apparatus according to claim 5 is characterized in that, comprising:
The 1st cooling device supplies to above-mentioned the 1st cooling tube with refrigerant from a side of above-mentioned gradient magnetic field coil;
The 2nd cooling device supplies to above-mentioned the 2nd cooling tube with refrigerant from another side of above-mentioned gradient magnetic field coil.
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